So you’re ready to build your own AR-15 upper but aren’t sure of the upper receiver?
We’ve got you covered with our personal go-to mil-spec receiver and also a couple of unique options that will turn heads.
If you haven’t read my AR-15 Guide that goes over all the components of an AR, I’d suggest starting there first. Otherwise, I’ll suppose that you’re well-versed in everything AR and ready to just see what’s the best upper receiver.
*Updated 2018*: More lightweight uppers.
Here’s a sneak peek of our best uppers list if you can’t wait:
- Best Mil-Spec: Aero Stripped Mil-Spec
- Mil-Spec Upgrade: Aero M4E1
- Best Slick Upper: Aero Slick
- More Accurate: VLTOR MUR
- Light & Reliable: Battle Arms Development Lighweight
- Lightest: F1 Firearms UDR-15-3G
Best AR-15 Upper Receivers
I’ve built almost a dozen AR-15 uppers for myself and friends and have almost exclusively gone with Aero Precision. They got their start manufacturing for the aerospace industry (name checks out) and moved into AR-15 parts. Now they are really gunning with complete AR-15’s and even barrels too.
Upper Receiver Forge Marks
You might have heard about forge marks, which are above the forward assist. This just designates which metal forging company created the upper blank. The end company (such as Aero) is the one that actually machines the upper.
So the forge mark by itself means nothing since the quality really comes from the final company (and there are differences). As far as I know, Aero uses several forges but mostly the “broken A” which comes from Anchor Harvey Aluminum.
1. Aero Stripped Upper Receiver
The gold standard ($80) in my mind that lets you choose your own forward assist and port door. Comes with M4 feedramps, laser engraved T-marks for the rails, and also available in several colors for a little bit more.
I’ve had no problems with any of my builds and if you do any searches you’ll see that it’s almost exclusively positive comments. Remember to finish out your stripped upper with an upper parts kit ($17)
2. Aero M4E1 Stripped Upper Receiver
The upgraded version of the mil-spec that gives a billet look without the doubling in price. My personal favorite now for my builds and what lives on my home defense gun (full review).
Remember to finish out your stripped upper with an upper parts kit ($17) or simply look at assembled uppers which are basically the same price with the upper parts installed.
No need to scrape anything when installing…or go nuts on the port door.
What’s your take?
3. Blemished Aero Uppers
And if you’re balling on a budget, you can get a “blemished” version (~25% off) of the stripped or assembled upper (depending on their stock). “Blemished” just means there’s some cosmetic abnormalities that will not affect actual function.
The last two builds I’ve done have been with Aero blem uppers and I had to really look to find the cosmetic problem. And of course they’ve all worked fine.
Here’s the latest one…looks like there’s a scuff & a dimple. I put more scuffs on mine during a match! If you want to save a couple bucks I’d go this route.
Bad thing is that they are usually snatched up as soon as they become available.
4. Aero Slick (No Forward Assist) Upper
If you have never used the forward assist and want to shave some weight off…you can get a no forward assist upper ($84). This type of upper is also known as a “slick” upper.
In my opinion I just like the look of the forward assist and I go by the mantra that I’d rather have it and not use it, than need it and not have it. Especially on a more duty rifle build.
5. VLTOR MUR Upper Receiver
The MUR upper receiver ($200) has thicker walls to make it a more rigid shooting platform which should translate to more accuracy. Plus it looks different and cool enough to get some envious looks.
6. Battle Arms Development
If you want to go light…but not at the expense of extreme lightening cuts and possible reduced reliability.
Plus…I dig the Tron-esque design.
7. F1 Firearms UDR-15-3G Upper Receiver
Prices accurate at time of writing
My newest muse…
Probably as light as you can go…and geared towards turning heads at rifle competitions (not home-defense). If you’re in a dusty environment I’d keep it covered…but otherwise initial reports say that the large cuts don’t affect function even with tons of rounds downrange.
One point I’d knock it down for is that you can’t use a Magpul BAD lever with it.
Here it is on my new competition upper.
Now that you’ve seen our suggestions for the best AR-15 upper receiver (both stripped and assembled), you’re one step closer to your build. Check out the rest of our AR- 15 Guides to continue your parts selection and overall education. And if you’re ready to build…here’s our AR-15 Upper Assembly Visual Guide.